The page advertises two separate packs to be released in November of this year and May 2015 for £7.00 each (about $11.60) that will feature characters from the Mario series, as well as two characters from the Animal Crossing series, as well as Link. The site also mentions the digital download will offer free delivery, because charging extra shipping on bits would just be silly.

Each add-on will also feature two cups with four courses each. There’s no word on if changes will be made to the game’s maligned battle mode.

Source: Nintendo Store UK

The leak comes the day before a free update that will include the Mercedes Benz-style kart already released in Japan and featured in this commercial:

We apologize for the nightmares inspired by that. Here’s the actual trailer Nintendo used in the U.S.

Here’s the entire content on the page, in case it is taken down.

About the AOC Pack
Each Add On Content pack will contain two new cups, each with four courses, which, in total, increases the number of available courses by 50 percent. The Add On Content packs include classics like Wario’s Gold Mine from Mario Kart Wii, as well as new courses, some taking place in the worlds of The Legend of Zelda and Animal Crossing. New vehicles will also arrive with each pack, including the Blue Falcon kart representing the F-Zero franchise in the first AOC pack.
Mario Kart 8 Pack 1 – Released: November 2014

Pack 1 includes:

3 Characters: Tanooki Mario, Cat Peach, Link

4 Vehicles

8 Courses

Mario Kart 8 Pack 2 – Released: May 2015

Pack 2 includes:

3 Characters: Villager, Isabelle, Dry Bowser

4 Vehicles

8 Courses

As a bonus for purchasing both packs – as a bundle or separately – you can get eight different-coloured Yoshis and eight different-coloured Shy Guys that can be used right away.